This invention relates to a header for cutting and transporting a standing crop and particularly to an arrangement which provides an improved draper canvas of the header.
Draper headers generally include a header frame, an elongate cutter bar along a front edge of the frame including a cutter bar beam which carries a plurality of knife guards for guiding reciprocating movement of a sickle knife across a front edge of the cutter bar. On the header is also mounted a draper assembly including a first and second draper guide roller each arranged at a respective end of the draper assembly spaced apart along the cutter bar with an axis of each roller extending substantially at right angles to the cutter bar, a draper canvas forming a continuous loop of flexible material wrapped around the rollers so as to define a front edge of the canvas adjacent the cutter bar, a rear edge of the canvas spaced rearwardly of the cutter bar, an upper run of the canvas on top of the roller and a lower run of the canvas below the rollers. The cut crop thus falls rearwardly onto the upper run of the canvas and is transported longitudinally of the header. Generally, between the draper rollers there is provided a support plate assembly for the upper run of the draper canvas to prevent sagging.
The header of this type can be used simply for forming a swath in which case the material is carried to a discharge opening of the header and deposited therefrom onto the ground. Headers of this type can also be used for feeding a combine harvester so that the materials are carried to an adapter member positioned at the discharge opening of the header for carrying the materials from the discharge opening into the feeder housing of the combine harvester. Yet further, headers of this type can be used for hay conditioners in which the material from the discharge opening is carried into crushing rolls. It will be appreciated, therefore, that the use of the header is not limited to particular types of agricultural machine but can be used with any such machine in which it is necessary to cut a standing crop and to transport that crop when cut longitudinally of the header for operation thereon.
The draper canvas normally comprises a fabric which is coated with a rubber material which is then vulcanized after forming of the fabric into the required shape and after attachment thereto of transverse slats.
An example of a prior art draper of this type is shown in U.S. Pat. No. 5,459,986 of Talbot and Fox issued Oct. 24, 1995 to the present assignee.
One problem with a draper construction of this type is to provide and effective guiding arrangement for the draper canvas to prevent it from sliding or twisting on the rollers forwardly or rearwardly of the cutter bar. While the above patent does not show or describe the conventional guiding arrangement for the draper canvas, in practice, this guide is formed by a bead or rib formed on the underside of the canvas that is side facing inwardly which rib runs in a groove provided on the rollers.
This arrangement has been used for many years and has been considered adequate but it has a number of disadvantages examples of which are as follows.
Firstly, the rib wears rapidly. Secondly the rib is only effective at the rollers and thus has no guiding effect in the long length between the rollers. Thirdly the forces at the roller are very high due to the fact that all of the guiding effect occurs at the rollers. Fourthly, if the groove becomes contaminated, the rib can be forced out of the groove.
Another problem which has required attention is that of reducing loss of material from the carrying surface of the canvas by escaping over the front edge between the front edge and the cutter bar.
It is one object of the present invention, therefore, to provide an improved header which allows a more effective guiding of the upper run of the draper canvas.
It is a further object of the present invention, therefore, to provide an improved header which includes an improved and more effective draper canvas.
It is a yet further object of the present invention, therefore, to provide an improved header which allows a more effective co-operation between the upper run of the draper canvas and the adjacent element of the cutter bar to reduce the possibility of escape of material therebetween.
According to one aspect of the invention there is provided a header for cutting and transporting a standing crop comprising:
a header frame;
an elongate cutter bar arranged along a front edge of the frame;
a knife mounted on the cutter bar for cutting the standing crop;
a draper assembly mounted on the header frame rearwardly of the cutter bar such that crop cut by the knife of the cutter bar falls onto the draper assembly for transportation longitudinally of the header;
the cutter bar including a trailing edge therealong adjacent the draper assembly;
the draper assembly including:
a first and a second draper guide roller each arranged at a respective end of the draper assembly spaced apart along the cutter bar with an axis of each guide roller arranged substantially at right angles to the cutter bar;
a draper canvas forming a continuous loop of flexible material wrapped around the rollers so as to define an upper run of the canvas on top of the rollers and a lower run of the canvas below the rollers, a front edge of the upper run of the canvas adjacent the cutter bar, a rear edge of the upper run of the canvas spaced rearwardly of the cutter bar, an inner surface of the canvas facing inwardly and an outer surface of the canvas facing outwardly such that the outer surface defines an upper surface of the upper run for carrying the cut crop thereon;
at least one of the guide rollers being arranged to effect driving of the canvas in a direction along its length to carry the cut crop therealong
the draper canvas having a guide bead therealong attached to and extending outwardly from the outer surface thereof;
the guide bead being arranged such that a forward side surface of the bead on the upper surface of the upper run of the canvas, as the canvas moves in its direction of movement, runs in contact with the trailing edge of the cutter bar to guide the location of the canvas relative to the cutter bar.
The term xe2x80x9ccanvas xe2x80x9d as used herein does not imply the use of specific material for the manufacture of the canvas since this term has become widely used as a term identifying the belts or sheets which carry the cut crop in a header of this general type.
While the knife used with the cutter bar is usually of the sickle knife type including a plurality of knife guards mounted on the cutter bar, other types of knife can also be used.
In some embodiments, the cutter bar itself comprises a channel shaped member which defines the trailing edge as an integral portion of the cutter bar itself. In other embodiments, the cutter bar forms in effect a single bar carrying the sickle knife with a separate canvas carrier element in the form of a plate attached to and carried by the cutter bar. In this latter arrangement, the trailing edge can be provided by the edge of the canvas carrier rather than the cutter bar itself. However it will be appreciated that in both arrangements the guide bead engages an edge which is fixed relative to the cutter bar and thus is guided in position relative to the cutter bar as it moves along the cutter bar.
Preferably the forward side surface of the bead is spaced rearwardly from the front edge of the canvas such that the front edge is located underneath the trailing edge of the cutter bar or canvas carrier.
Preferably there is provided a rear plate adjacent the rear edge of the upper run of the canvas, wherein the draper canvas has a second guide bead therealong attached to and extending outwardly from the outer surface thereof, the second guide bead being arranged such that a rear side surface of the second guide bead on the upper surface of the upper run of the canvas, as the canvas moves in its direction of movement, runs in contact with a front edge of the rear plate to guide the location of the canvas relative to the rear plate.
Preferably the rear side surface of the second guide bead is spaced forwardly from the rear edge of the canvas such that the rear edge is located underneath the front edge of the rear plate.
Preferably the outer surface of the canvas carries a plurality of slats thereon at spaced positions along the length of the canvas and extending at right angles to the guide bead, the slats being formed integrally with the bead so as to be connected thereto. Where the draper canvas has a second guide bead therealong attached to and extending outwardly from the outer surface thereof parallel to and spaced rearwardly from the guide bead, the slats are formed integrally with both the guide beads so as to be connected thereto.
Preferably the guide bead is continuous along the length of the canvas and has a series of cut out portions at spaced positions along the length of the canvas such that an outer surface of the guide bead is castelated to form portions of reduced height of the bead.
As the guide beads are provided on the outer surface, the inner surface of the canvas is flat and free from beads.
In the arrangement where the forward surface of the guide bead is spaced rearwardly from the front edge of the canvas, there is preferably provided a front draper support plate defining a substantially horizontal support surface lying under the upper run adjacent the front edge thereof and extending therealong between the first and second guide rollers, the first and second guide rollers each having a front end thereof recessed rearwardly of the front edge of the upper run of the draper canvas and the support plate having a front edge thereof recessed rearwardly of the front edge of the upper run of the draper canvas such that the upper run of the draper canvas includes a portion thereof at the front edge which is cantilevered forwardly of the rollers and of the support plate, the trailing edge of the cutter bar extending rearwardly over the upper run of the draper canvas to a position rearwardly of the front edge of the upper run of the draper canvas and forwardly of the front end of the rollers and of the front edge of the support plate and engaging said portion of the draper canvas for forming a seal therewith to inhibit entry between the cutter bar and the draper canvas of materials carried by the cut crop.
According to a second aspect of the invention there is provided a draper canvas for a header having a cutter bar, the canvas comprising an elongate strip of flexible material for wrapping around draper guide rollers so as to define an upper run of the canvas on top of the rollers and a lower run of the canvas below the rollers, a front edge of the upper run of the canvas adjacent the cutter bar, a rear edge of the upper run of the canvas spaced rearwardly of the cutter bar, an inner surface of the canvas facing inwardly and an outer surface of the canvas facing outwardly such that the outer surface defines an upper surface of the upper run for carrying the cut crop thereon, the draper canvas having a raised rib extending therealong attached to and extending outwardly from the outer surface thereof at or adjacent the front edge thereof.
According to a third aspect of the invention there is provided a header for cutting and transporting a standing crop comprising:
a header frame;
an elongate cutter bar arranged along a front edge of the frame;
a knife mounted on the cutter bar for cutting the standing crop;
a draper assembly mounted on the header frame rearwardly of the cutter bar such that crop cut by the knife of the cutter bar falls onto the draper assembly for transportation longitudinally of the header;
the cutter bar including a trailing edge therealong adjacent the draper assembly;
the draper assembly including:
a first and a second draper guide roller each arranged at a respective end of the draper assembly spaced apart along the cutter bar with an axis of each guide roller arranged substantially at right angles to the cutter bar;
a draper canvas forming a continuous loop of flexible material wrapped around the rollers so as to define an upper run of the canvas on top of the rollers and a lower run of the canvas below the rollers, a front edge of the upper run of the canvas adjacent the cutter bar, a rear edge of the upper run of the canvas spaced rearwardly of the cutter bar, an inner surface of the canvas facing inwardly and an outer surface of the canvas facing outwardly such that the outer surface defines an upper surface of the upper run for carrying the cut crop thereon;
at least one of the guide rollers being arranged to effect driving of the canvas in a direction along its length to carry the cut crop therealong
the draper canvas having a raised rib therealong attached to and extending outwardly from the outer surface thereof at or adjacent the front edge.